Hyaluronidases are a family of enzymes that hydrolyze hyaluronic acid. They are carbohydrate digestive enzymes that cleave the glycoside bond of carbohydrates, and are also called “mucinases or spreading factors”. The kind of hyaluronidases includes endohexosaminidase types, endoglucuronidase types, endohexosamine cleavage types and endoglucosamine cleavage types. These hyaluronidases are present in the testis or sperm of the higher animal, lysosomes of the liver, snake venom, Klebsiella pneumoniae, or Streptococcus. Meanwhile, the connective tissue of the skin comprises collagen, hyaluronic acid polysaccharide, and the like. Hyaluronidases are enzymes that degrade the hyaluronic acid, and the activation of hyaluronidases causes the hyaluronic acid of skin connective tissue to degrade, and thus, make the skin connective tissue loose to reduce skin elasticity and cause wrinkles.
In the prior art for preventing the skin connective tissue from being loose, there is a method comprising treating the skin with vitamins A, C, E, and the like to stimulate collagen synthesis and prevent oxidation. However, this method has disadvantages in that these vitamins are expensive and are easily degraded in the external environment to make their long-term storage difficult. Also, methods including applying collagen directly to the skin or orally administering collagen were suggested but have no demonstrated effects. In addition, there is a method comprising treating the skin with an extract of plants, such as Areca catechu, Moutan cortex, and the like, which have hyaluronidase inhibitory effects. However, this method has the disadvantage of reduced economical efficiency, because it comprises cultivating plants and extracting an active ingredient from the cultivated plants.
Meanwhile, PGA is a mucous polymer consisting of D,L-glutamic acid bound to gamma-glutamyl and is produced by microorganisms. Specifically, PGA is produced from the genus Bacillus. strain isolated from Chungkookjang (Korean traditional fermented soybean food prepared using rice-straw), Natto (Japanese traditional fermented soybean food), Kinema (fermented soybean food prepared in Nepal), etc. PGA produced from the genus Bacillus strain is an edible, water-soluble, anionic and biodegradable polymer substance, which can be used as a raw material for humectants, moisturizers and cosmetics. Recently, studies on the use of PGA to develop materials substituting for non-degradable polymers and heat-resistant plastics by esterification and produce water-soluble fibers and membranes have been performed in developed countries.
In addition, studies reported on PGA include the effect of manganese ions on the production of PGA, the use of PGA as water-soluble polymer by ultrasonic degradation, and the development of low-water-soluble plastics by the synthesis of ester derivatives (Biosci. Biotechnol. Biochem., 60:1239, 1996).
In prior patents relating to the use of PGA, Japanese Patent Laid-Open Publication No. Hei 6-32742 discloses the production of PGA by Bacillus subtillis, and its use in health food having the effect of treating osteoporosis, such as a calcium-dissolving agent. European Patent No. 838160 discloses that PGA has the effect of reducing water contamination by reducing the content of phosphorus in water. Also, Japanese Patent Laid-Open Publication Nos. Hei 10-251402, 7-300522 and 6-322358 disclose the applications in hygienic products (e.g., diapers), food products and horticulture by preparing an absorptive and biodegradable resin with high gelatination rate and water absorption using PGA by irradiation of radiation. Also, it is known to use PGA as solidified biodegradable fibers, films or film moldings by the dissolution, precipitation and drying of PGA (Japanese Patent Laid-Open Publication Nos. Hei 7-138364 and 5-117388). In addition, the use of PGA as a polymer for drug carriers is known (Japanese Patent Laid-Open Publication Nos. Hei 6-92870 and 6-256220).
Meanwhile, the present inventors obtained a patent relating to a method for producing PGA using a halophilic Bacillus subtilis var. chungkookjang that produces PGA with high molecular weight (Korean Patent Registration No. 500,796). Also, we obtained patents relating to an anticancer composition, an immune adjuvant and an immune enhancing agent, which contain PGA (Korean Patent Registration Nos. 496,606; 517,114; and 475,406). In addition, we have been conducting studies on another use of PGA.
Thus, the present inventors have made extensive efforts to find other functions of PGA having the above-described various effects, as a result, found that PGA inhibits hyaluronidase that degrades hyaluronic acid, which is a component of skin connective tissue, and thus it can help to maintain the elasticity of the skin, and also it has good humectant and moisturizing properties and excellent skin compatibility, thereby completing the present invention.